We have used Thrifty several times based on price and were pleased. I HATE shuttles, but theirs is painless. It's usually already waiting there for you. The lines were not bad, and we joined Blue Chip (free) to prevent them after renting a couple of times. They've given us a few free upgrades, too. The only slight negative was getting an agent once who was really snotty about the insurance, but that can happen anywhere. Now that we're Blue Chip, that's not even an issue.
Barb